Strobe Tuner for Mac

From Katsura Shareware:

Strobe Tuner is a 12-note chromatic scale strobe tuner that utilizes sound input devices such as built-in microphone, line-in, and iSight. You can use Strobe Tuner to tune your guitar, bass, and other musical instruments.

Strobe tuners are extremely accurate compare to regular tuners with a needle or LEDs. The slightest difference between the actual pitch and the ideal pitch accumulates over time and appears as a movement on the strobe tuning meter.

• Tuning: 12-note chromatic scale
• Temperaments: Equal Tempered, Kellner, Kirnberger III, Meantone, Pythagorean, Vallotti, Werckmeister III, Young II, etc.
• Meters: strobe, cent, and hertz.
• Range: A0 (27.5Hz) - C8 (4186.0Hz)
• Calibration: 349.0 - 499.9Hz (0.1Hz steps)
• Accuracy: +/- 1 cent with the cent readout. +/-0.1 cent @ 440Hz with the strobe tuning meter.
• Transpose: +/-11 semitones
• Resizable main window on Mac OS X 10.4 or later